diff --git a/docs/conf.py b/docs/conf.py
index 9e306f6..01e808d 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 import datetime
+import json
 import os
 
 from sphinx.ext import autodoc